iOS多线程之GCD

 1 //
 2 //  YYViewController.m
 3 //  08-GCD基本使用
 4 //
 5 //  Created by apple on 14-6-24.
 6 //  Copyright (c) 2014年 itcase. All rights reserved.
 7 //
 8 
 9 #import "YYViewController.h"
10 
11 @interface YYViewController ()
12 
13 @end
14 
15 @implementation YYViewController
16 
17 - (void)viewDidLoad
18 {
19     [super viewDidLoad];
20     //1.获得全局的并发队列
21    dispatch_queue_t queue =  dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
22     //2.添加任务到队列中，就可以执行任务
23     //异步函数：具备开启新线程的能力
24     dispatch_async(queue, ^{
25         NSLog(@"下载图片1----%@",[NSThread currentThread]);
26     });
27     dispatch_async(queue, ^{
28         NSLog(@"下载图片2----%@",[NSThread currentThread]);
29     });
30     dispatch_async(queue, ^{
31         NSLog(@"下载图片2----%@",[NSThread currentThread]);
32     });
33 //打印主线程
34     NSLog(@"主线程----%@",[NSThread mainThread]);
35     
36 }
37 
38 @end

 1 //
 2 //  YYViewController.m
 3 //  09—GCD基本使用2
 4 //
 5 //  Created by apple on 14-6-24.
 6 //  Copyright (c) 2014年 itcase. All rights reserved.
 7 //
 8 
 9 #import "YYViewController.h"
10 
11 @interface YYViewController ()
12 
13 @end
14 
15 @implementation YYViewController
16 
17 - (void)viewDidLoad
18 {
19     [super viewDidLoad];
20     
21     //打印主线程
22     NSLog(@"主线程----%@",[NSThread mainThread]);
23     
24     //创建串行队列
25     dispatch_queue_t  queue= dispatch_queue_create("wendingding", NULL);
26     //第一个参数为串行队列的名称，是c语言的字符串
27     //第二个参数为队列的属性，一般来说串行队列不需要赋值任何属性，所以通常传空值（NULL）
28     
29     //2.添加任务到队列中执行
30     dispatch_async(queue, ^{
31         NSLog(@"下载图片1----%@",[NSThread currentThread]);
32     });
33     dispatch_async(queue, ^{
34         NSLog(@"下载图片2----%@",[NSThread currentThread]);
35     });
36     dispatch_async(queue, ^{
37         NSLog(@"下载图片2----%@",[NSThread currentThread]);
38     });
39     
40     //3.释放资源
41 //    dispatch_release(queue);
42 }
43 
44 @end

 1 //
 2 //  YYViewController.m
 3 //  10-CGD基本使用3
 4 //
 5 //  Created by apple on 14-6-24.
 6 //  Copyright (c) 2014年 itcase. All rights reserved.
 7 //
 8 
 9 #import "YYViewController.h"
10 
11 @interface YYViewController ()
12 
13 @end
14 
15 @implementation YYViewController
16 /**
17  *  用同步函数往并发队列中添加任务
18  */
19 - (void)viewDidLoad
20 {
21     [super viewDidLoad];
22     
23     //打印主线程
24     NSLog(@"主线程----%@",[NSThread mainThread]);
25     
26     //创建串行队列
27     dispatch_queue_t  queue= dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
28 
29     
30     //2.添加任务到队列中执行
31     dispatch_sync(queue, ^{
32         NSLog(@"下载图片1----%@",[NSThread currentThread]);
33     });
34     dispatch_sync(queue, ^{
35         NSLog(@"下载图片2----%@",[NSThread currentThread]);
36     });
37     dispatch_sync(queue, ^{
38         NSLog(@"下载图片3----%@",[NSThread currentThread]);
39     });
40 }
41 
42 @end

 1 //
 2 //  YYViewController.m
 3 //  11—CGD基本使用4
 4 //
 5 //  Created by apple on 14-6-24.
 6 //  Copyright (c) 2014年 itcase. All rights reserved.
 7 //
 8 
 9 #import "YYViewController.h"
10 
11 @interface YYViewController ()
12 
13 @end
14 
15 @implementation YYViewController
16 
17 
18 /**
19  *用同步函数往串行队列中添加任务
20  */
21 - (void)viewDidLoad
22 {
23     [super viewDidLoad];
24      NSLog(@"用同步函数往串行队列中添加任务");
25     //打印主线程
26     NSLog(@"主线程----%@",[NSThread mainThread]);
27     
28     //创建串行队列
29     dispatch_queue_t  queue= dispatch_queue_create("wendingding", NULL);
30     
31     //2.添加任务到队列中执行
32     dispatch_sync(queue, ^{
33         NSLog(@"下载图片1----%@",[NSThread currentThread]);
34     });
35     dispatch_sync(queue, ^{
36         NSLog(@"下载图片2----%@",[NSThread currentThread]);
37     });
38     dispatch_sync(queue, ^{
39         NSLog(@"下载图片3----%@",[NSThread currentThread]);
40     });
41 }
42 
43 @end